Read head assembly for coded markings



y 1970 J. CASTALDI 3,519,832

READ HEAD ASSEMBLY FOR CQDED MARKINGS Filed NOV. 6, 1967 6 Sheets-Sheet1 INVENTOR. JOHN CflS 74!- U! ATTORNEK? July 7, 1970 J. CASTALDI3,519,332

READ HEAD ASSEMBLY FOR CODED MARKINGS Filed Nov. 6, 1967 6 Shets-Sheet zF|G.3 FIGBa INVENTOR. JOHN CA5 TAL 0! BY g July 7, 1970 J. CASTALDI READHEAD ASSEMBLY FOR CODED MARKINGS 6 Sheets-Sheet. 5

Filed Nov. 6, 1967 INVENTOR. Jan/v cm $741.0!

ATTORNEYS July 7, 1970 r J. CASTALDI 3,519,832 I READ HEAD ASSEMBLY FORCODED MARKINGS Filed Nov. 6, 1967 6 Sheets-Sheet 4 SCAN ASSEMBLY F iG.6

\ACOUIRE FOLDER HORIZ. I

V wave 5 I mum: CONTRQI- I vm'ncm. we mo INVENTOR. I JOHN CASTALDI reignlas lat?! 1133 BY 44 ,q, FIG. 7A 4 W July 7, 1970 J. CASTALDI 3,519,832

READ HEAD ASSEMBLY FOR CODED MARKINGS Filed Nov. 6, 1967 6 Sheets-Sheet5 INVENTOR. JOHN CA S TALDI BY g A T TORNE Y5 Filed Nov. 6, 1967 J.CASTALDI READ HEAD ASSEMBLY FOR 000m) mmxmes 6 Sheets-Sheet 6 ALIGN-MEN? STOP TO ANNUNCIAT OR LIMIT SWITCHIS I32 124 amwsre STORE EJECTCONTROL CONVERTER Imam mac" not nu ma" nevaomo DRIVE MOTOR CONTROLVANWNCIATOR DRIVE MOTOR NOT FOUND r LOGIC muuncmon 40 EJECT B EnliC 'l'1 I33 aunen K FIG. 9

TO ANNUNCIATOR TO BUFFER i i i EJECT STORE convim'ia' CONTROL cowen'rs RMEMORY READ KEYBOARD INVENTORY B UFFER PLATFORM scAu mrrmrons REMOTEREAD PLATFORM KEY REMOTE READ PLATFORM v DISPLAY FIG. 9a

JOHN CAS TALOI 1N VENTOR.

ATTORNEYS United States Patent 3,519,832 I READ HEAD ASSEMBLY FOR CODEDMARKINGS John Castaldi, Brooklyn, N.Y., assignor to Supreme Equipment &Systems Corporation Continuation-impart of application Ser. No. 430,330,Feb. 4, 1965. This application Nov. 6, 1967, Ser. No. 680,642

Int. Cl. G01n 21/26; G02b 5/14 US. Cl. 250-219 4 Claims ABSTRACT OF THEDISCLOSURE cooperation with an array of folder guiding slots. Manualentry of the file folders into the store is random. and may take placesimultaneously with the automatic withdrawal. Towards this end, afeed-through access is provided which automatically gates and raises themagnetic'clutches to permit ejection of the desired folder. Furtherrefinements described include ejected folder collection; automaticinput; a memory adjunct; and remote signalling.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is acontinuation-in-part to my copending application, Ser. No. 430,330,filed Feb. 4, 1965 and entitled Automatic Locating Device.

BACKGROUND OF THE INVENTION The present invention relates generally todata and information handling systems and more particularly to anapparatus for storing and retrieving information.

While it is possible to store largemasses of information in conventionalcomputer memories, such as-matrices and drums, and even larger amountsof information on magnetic storage reels, it is often desirable, if. notnecessary, to resort to the document itself. Microfilming provides apartial solution but is unsatisfactory where production of the originalis requisite. Examples abound in todays commerce and include commercialpaper of all types, mortgages, deeds, stock, bonds, notes, proofs ofaudit, etc.

Additionally, entire files containing ten or a hundred or more pieces ofpaper may require review inthe form of back-and-forth huntingwhichrenders computer memorized information impractical.

As a consequence of the foregoing, in recent years there has arisen anumber of systems capable of storing and retrieving information in itsoriginal form. While these arrangements partially obviate objections tostores of .the

information-memorizing type, many endeavors in this, di-

rection have created more problems than they have solved. For example, amajority of the original document-retrieving systems disposed theinformationswithin storage racks at addresses memorized by a computer.The computer is then fed with the information denoting thedesired docu-3,519,832 Patented July 7, 1970 ment, and internally cross indexes to anaddress to which it directs a remote searching unit.

Where a large number of documents are involved, this type system isextremely cumbersome since each file must be returned to its properaddress location. Hence, greater time is spent in returning the filethan in obtaining it.

The documents may be filed at random and the search mechanism caused toscan each document face for an imprinted code number, e.g., magneticallyor optically, and eject the sought document. This type of an arrangementrequires a complex mechanical feed system in order to render visible anarea on the face of each document sufficient to store and read therecorded number.

The most recent innovation in the latter type random access system ismechanisms capable of reading codes which appear upon the edge of thedocument or file. Since the codes may be magnetically or opticallyrecorded, it is possible to scan the file edges at high speed. Whilethese arrangements are an improvement over those recited earlier, theyare still in their incipient stage and leave much to be desired in termsof speed, flexibility, alignment, edge-reading capability, documentejection, automation, synchronization and so on.

While the foregoing discussion has been directed primarily to originaldocuments and filefolders, it will be appreciated that it applies withlike import to almost any material capable of being stored and acquiredautomatically. For purposes of simplicity, such materials shall begenerically referred to hereinafter as items.

OBJECTS OF THE INVENTION It is the object of this invention to providean improved random access storage system capable of identifying andacquiring items designated by specific code numbers recorded on the edgethereof.

It is a further object of this invention to satisfy the foregoing objectwith a system which is simple and economical to manufacture and maintain.and which is sufficiently flexible in concept to permit adaptability tovarious types of stored items.

It is a further object of this invention to provide a sensing mechanismfor the edge coatings which is accurate, reliable, and which is capableof being sufiiciently remote to avoid interference with the mechanicalfunctioning of the acquisition means. I

It is a further object of this invention to increase the access speed inwhich the search mechanism finds and acquires the desired item.

It is a still further object of this invention to provide a randomaccess storage system which may be simply and economically automated andfunctionally expanded.

SUMMARY OF THE INVENTION Briefly, the invention is predicated upon theconcept of providing an optical sensing mechanism capable of rectionedwithin predetermined limits. The magnetic mechanism may be repositionedautomatically to permit simultaneous insertion and withdrawal of itemsfrom pposite sides of the stack.

Automation is provided by a return mechanism which acquires on the basisof read head sight interference by an ejected folder. Computer typememories are added which can store the present posture of items and canbe remotely triggered to alter the memorized data to reflect a change incondition.

The above mentioned and other features and objects of this invention andthe manner of attaining them will become more apparent and the inventionitself will best be understood by reference to the following descriptionof embodiments of the invention taken in conjunction with theaccompanying drawings, the description of which follows:

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective illustration of theexterior of a random access store in accordance with one embodiment ofthe invention.

FIG. 2 is a perspective detail of the file folder guide slots, magneticclutch and scanning assembly of FIG. 1.

FIG. 2a illustrates an alternative arrangement for inserting edgealignment.

' FIG. 3 schematically illustrates a single read head.

FIG. 3a shows a practical read head arrangement for achieving the samefunctional result as that shown in FIG. 3.

FIG. 4 is a perspective illustration of a sectioned read head assemblyaccording to the invention.

FIG. 5 shows the cable assembly for synchronizing the scan assemblies.

FIG. 6 illustrates various positions in the umbilical cable linking ascan assembly to a terminating block in the storage rack.

FIG. 7 is a perspective illustration of an acquisition and file folderreturn mechanism which may be used in conjunction with the invention.

FIG. 7a is a block diagram illustrating the electronic control of themechanism of FIG. 7.

FIG. 8 is a perspective illustration of a second embodiment of theinvention wherein file folders may be acquired and inserted throughopposing sides of the storage rack.

FIG. 8a is a perspective detail of a scanning assembly and rack portionin FIG. 8.

FIG. 9 is a block diagram of the electric circuits controlling therandom access store according to the invention, and

FIG. 9a is a block diagram of a portion of the circuit shown in FIG. 9,modified to provide computerized functions.

DETAILED DESCRIPTION OF THE INVENTION The general organization of theinvention is shown perspectively in FIG. 1. For purposes ofillustration, three vertically stacked racks 10, 11 and 12 are shown. Aswill be appreciated from the description, any number of vertical racksmay be simultaneously treated by the same control panel; further, theseracks may be iterated horizontally.

, The racks are separated by spacers 10, 11' and 12' which contain thescanning assemblies A, B and C (see FIG; 5). The rack ends abut theproximate and distally located end sections 14 and 16 which house thescanning assembly drive motors and transmissions (shown in detail inFIG. 5). The rack ends also include terminating blocks (such asgenerally referred to in FIG. 6) for coupling between the console 20 andthe racks, and between stationary rack portions and the scanningassemblies. The scanning assemblies contain the scanning or read headassemblies and shuttle between the rack ends 14 and 16 via the opposingspacers (such as 10' and 10", see FIG.

2) which act as guides. The assemblies are driven by a unique cabledrive arrangement (as will be explained) which simultaneously advancesthe assemblies in each rack.

FIGS. 6 and 2 illustrate how communication is afforded between a rackterminal and the uppermost scanning assembly A. In the former figure, byuse of phantom lines, the assembly is shown in three positions; middle,proximate, and distal. Since the scan assemblies which house the headsand associated ejection equipment travel the length of the system asshown, it is important to couple them electrically (via the rack ends)to the console in such a manner that the cable is played in and outwithout tension, regardless of the position of the scanning assembly.

Such an arrangement is provided as follows. Below each shuttle assemblyis provided a trough 19 in which a ribbon-like multi-conductor cable 21is laid (as shown in the figures) so as to double back on itself whenthe assembly advances to the cable termination in the rack end. Toinsure that a double back is initiated and the cable does not kink uponreturn of the head to the terminated end, a belly 21' is allowed at themost distant scan assembly position. Ribbon cable 21, upon exiting fromthe scanning head assembly A, is dressed along the L-shaped bracket 62to a point above the trough 19 for permitting the double back cablelay-in as explained previously.

The described arrangement obviates contact noise normally associatedwith commutator type arrangements. It further obviates the problem ofvariable resistance as the head moves from one end to the other along atranslator, and the necessity of pulleys at either end to maintain cabletension and position.

Console 20 is the functional hub of the system, and it is here that theoperator sits when controlling the random access store. Preferably, theconsole contains the associated electronic equipment in module plug-inform (e.g., 22) for ease in maintenance.

The console top includes a keyboard 30 having 10 numeric keys 36 forserial insertion of the code number representing the desired item. Aswill be explained hereinafter, the serial input is converted to a binarypresentation, to a buffer storage device for comparison with theoptically read signal emanating from the item scanning assembly.

Aside from the numeric digits, the keyboard also contains an on-off key31; a tape key 32 (whose function will be explained); a clear key 33 fornegating errors in the .number insertion; and a search key 34 forinitiating the search once the desired number has been properly keyedin.

The console top also contains an annunciator 40 for indicating to theoperator a variety of functions and machine conditions. For example, oneannunciator expression would be not in file to indicate that the searchhas been completed unsuccessfully. Alternatively, folder found would beannunciated. Other indications to the operator would be alignment stopwhich, as will be explained, occurs upon the scanning of a misalignedfolder, stopping the searching mechanism, so that the folder may bemanually aligned to obviate errors. As the system is functionallyexpanded, additional annunciated phrases would be added.

The console top may also contain the tape reader 45, commonly called aTD, for the automatic insertion of several code numbers representingseveral desired items. The TD may be any of the known types withconversion means being supplied to ensure coincidence with the numericsystem being utilized. Magnetic tape, punched cards, etc., inputs may beused instead of a TD as will be apparent to those skilled in the art. Adetailed explanation of the functioning of this equipment may be foundhereinafter with reference to FIG. 9.

FIG. 2 illustrates the cooperation between the most significant partsofthe invention. A file folder '49 has been chosen as the item. ItComprises a plastic frame 41 having mounted therein an expandable insert42 for adapting to variably thick records. The folders configuration isgenerally rectangular save for a depending lip or fin 43 at the bottomof the folder for slidably engaging one of a series of closely spacedgullies 44 in the squared corrugated bottom of each rack 35. The squaredcorrugations are formed of a hard, low-friction material and appear inedge view as repetitive square waves.

, An elongated magnet 37 is mounted at the rear vertical wall 38 of eachrack to run coextensive therewith. This magnet engages a metallic member46 aflixed to the rear side of the folder 49. Upon insertion of thefolder into the rack, the lower fin 43 first engages one of the gulliesin the corrugated rack bottom, the rear of the folder then becomingsecured magnetically to the back of the rack.

1 Thus, upon insertion of the full folder into the rack, it willmaintain its initial position regardless of the density of the folders.That is, notwithstanding that the file folders may not be contiguous,they will maintain their initial attitude without falling over. In orderto insure that the folder is not inserted in such a manner as to avoidengagement of the magnetic members, the fin 43 may be made sufficientlydeep (as are the gullies 44) so that the angular play of the folder topis reduced below that which would carry the metallic member 46 beyondreach of the magnet 37. The foregoing arrangement obviatesthe foldersattaining such an angle from orthogonal that the read heads on the scanassembly are unable to ascertain the information displayed on the foldertop (although this angle has been found to be quite large).

An alternative arrangement is shown in FIG. 2a where a T-shaped member83, 84 is affixed to insert 42 (which may now be deemed the item). Theupper horizontal portion of the T, 84, is sufficiently wide with respectto equi-spaced rods 81 that the item is caused to gravitationally dependfrom the rods. With this arrangement, the item may be easily slipped inand out of the rack. Magnet 37 and metal piece 85 can be included toprovide a positive backstop, if desired.

The folder top or cross bar contains the optically coded informationwhich describes the items. In the embodiment shown, it has been chosento use four groups ofbinary digits (see dashed lines, FIG. 4), eachrepresenting one conventional base 10 digit. Each group of binary digitsis made up of four areas each of which is either black or white,depending upon its informational content. A white area (e.g., 47)represents the binary one and a black area lbinary zero. Thus, thedigital number would be represented by black-whiteblack -white. Sixteenbinary areas give a four conventional digit capability; i.e., thecapability to store and search 9,999 file folders. Where this issufficient, four more binary positions maybe added to multiply the filestoring capability by ten.

While straight numeric to binary conversion would permit greaterpermutations and hence a greater number of identified file folders perbinary coded bit, the arrangement described has been found moreconvenient and more easily interpreted by the personnel involved. Theactual implantation of the areas may be simply effected by painting thetop black or applying a piece of black tape over the top area to bescanned by the optical read heads and then applying a white reflectivetape (e.g. 47) at positions where binary ones are to be present. Thepreferred type of white reflective tape is one such as Retroreflectiveby 3 M Corporation which contains millions of non-aligned dispersedreflective surfaces so that regardless of which direction the incidentlight falls, reflection is assured in all directions.

Along with the code on the surface of the folder, there is included aso-called read command .bit 48 (FIG. 4). This bit is simply a thin whitearea linearly aligned with the folder top and approximatelycentrallylocated between the folder edges. The bit may be placedanywhere in the binary but is preferably at the end of the code asshown. It is associated with a particular. read head whose function isto trigger the reading of the entire head assembly. In other words,rather than depend upon the arbitrary triggering of the read heads oneat a time as they view their respective area, one head is chosen whichis unrelated to the binary code and which may trigger the entire readhead assembly (in any well known manner) when the heads are centrallydisposed with respect to the folder.

It will sometimes occur that a folder is not placed sufficiently farinto the rack to engage against the magnetic back stop. When thishappens, one of two situations will occur. Either the folder will onlybe slightly removed from its home position so that the heads will stillread correctly, or the folder will be sufliciently removed from the homeposition so that hits will. be misread. In order to obviate the latterevent, a separate read head is offset a predetermined distance X from a.white indicia area 45 which precedes the code.

The length X is that length within which the apparatus will stillcorrectly analyze the fold-er regardless of slight misalignment. Thewidth of the white indicia area 45 is that width within which an errorwill occur if the reading is taken upon issuance of a read commandsignal by the head associated with area 48. As will be appreciated bythose versed in the art, the output from the read head associated witharea 45 may be led to a logical OR circuit of the exclusive type inconjunction with the read command signal so that a read command signalis effectively negatived during misalignment.

When the folder juts out, beyond the area within which the area 45 maybe seen by the associated read head, the dimensional relationships aresuch that the read command signal is also out of range of its associatedhead and the folder is treated by the apparatus as a normally ejectedfolder; i.e., it is not read. In other words, within the distance Xreading is permitted and within the distance X plus the width of thebright area 45, no reading will take place due to a negativing of theread command signal.

It may be noted that no skew type misalignment is contemplated and onlymisalignment in the rectilinear sense is treated. This arises becausethe rack height is chosen to be dimensionally insuflicient to permitinsertion of the folder in any other manner than with the folder fin ina gully.

The scanning assembly The scanning assembly, an exemplary one of whichis shown in FIG. 2, contains the file ejection mechanism 65, 66 as wellas a plurality of linearly arranged read heads (generally depicted as68). The latter will be explained in greater detail in a subsequentportion of this specification. Each scanning assembly rides between apair of E-cross section guides 10 and 10" (previously referred to ingeneral terms as spacers), the central horizontal arm of the E providingbearing surfaces for four pairs of orthogonal guide rollers, the fronttwo of which (52, 55) are shown.

Upon an effective comparison being made between the sought file folderand that recognized by the reading heads (in a manner to be described),the lever arm 65 is actuated to eject the file folder. Since it is theobject of the ejection to leave the file folder jutting out a predetermined distance from the magnetic back stop, it has been foundpreferable to use a high torque, low speed drive. The reverse, a lowtorque, high speed drive has been found to be ineffective with heavyfolders and overeffective, to the point of throwing the file folders offthe ,racks, for light files.

.The high torque, low speed combination may be effected by amotor-lead-screw combination 66 of the conventional type. A motor speedof approximately 6,000

r.p.m. with a lead screw pitch suitable to providing a lever advance ofinches per second has been found adequate both as to size andperformance. Retrograde of the lever arm 65 and motor shut off areelfected, for example, by limit switches 78 and 79 in the well knownmanner.

Shuttling of the scanning assembly between the rack ends is controlledby cables 71, 72, 73 and 74. FIG. 5 traces a cable arrangement forsimultaneously advancing three vertically aligned scanning assembliesfrom a single motor drive. Each of the scanning assemblies is supportedin the manner previousl described (not shown in FIG. 5) and are drivenin common from a single drive drum 80 which in turn is driven, via thespeed reducing pulley arrangement 81, by motor 82.

Starting, for example, at the lowermost cable position, the cable is ledaround pulleys 91 and 92 disposed in the rear rack end 16 to points Cand C where it is aflixed to the lower scanning assembly C (e.g., bycrimping in a lanced assembly portion as shown). From the points ofaffixation, a cable is led around pulley 93 and is then free runningthrough scanning assembly C to the orthogonally disposed pulley 94. Atthe front portion of assembly C, the upper cable is affixed at points Cand C the lower cable is free running.

The arrangement is similar with respect to the upper scanning assemblyA; the cable again being aflixed to the scanning assembly at diagonallyopposite points to drive the scanning assembly in the same direction.

The relationship of the main driving drum 80 to the cable is exemplifiedby the following. The cable affixed to scanning assembly B at points Band B is led around pulley 85 under idler-and-positioning pulley 86 180about the drum 80, thence about idler 87, another 180 about drum 80, andthence via pulleys 88 and 89 free running through scanning assembly B.The rear end of scanning assembly B is similarly treated with respect tothe driving drum 80 via corresponding rollers (shown partially). Idler87 and its counterpart (not shown) at the front portion of the drum alsoserve, by varying their axial distance from the drum, as cabletensioning means. The tensioning may be simply eifectuated by a turnscrew 77.

The described arrangement allows a single drive drum and cable toadvance and retrograde a plurality of scanning assemblies. The use ofone continuous cable avoids cocking and jamming of the assemblies intheir guides due to unequal cable loads and unequal cable expansion. Theuse of the single drive further obviates the necessity for separatemotor control systems which would multiply by an order of magnitude theauxiliary equipment.

The described arrangement permits the simultaneous and synchronousadvancement of a plurality of scanning assemblies without cooking andjamming normally asso ciated with long runs of driven equipment having asubstantial transverse dimension.

The scan or read heads One of the basic components of applicantsinvention is the optical read head system. As previously discussed, thecode may be in either alpha or numeric form with discrete areas, eachviewed by a particular read head. As described, binary notation has beenchosen as preferable with Retroreflective tape being applied to thoseareas where a binary one is to be indicated.

As indicated generally by the arrow 68 in FIG. 2, the optical read headsare formed into a linear array of sensing positions. FIG. 3 is adetailed schematic of one such sensing position. A source ofillumination 101 transmits its light through a semi-transparent mirror102 onto file folder area 103. If this particular area is coded with theRetroreflective tape, light is reflected off the surface back up to thesemi-transparent mirror 102 where it is reflected to transducer 104which converts the light energy into electrical energy. It has beenfound preferable to have the light source and transducer on orthogonalaxes with the semi-transparent mirror being at 45 to each of these axes.The surface to be analyzed may be along eitherof these axes.

The described arrangement provides a very significant advantage. Theincident and reflected light beams are substantially along the same path105. Consequently, regardless of the distance between the folder and thesensing device (presuming reflected light is above the noise thresholdof the transducer) sensing may take place. Further, as will bedescribed, axis need not be perpendicular to the plane of the reflectedarea 103. Consequently, the read heads may be angled to view an area inadvance of the scanning mechanism, thus allowing for great flexibilityin the positioning of the ejection lever, vis-a-vis the scanned filefolder.

A similar functional result is achieved by the arrangement in FIG. 3a. Apair of fiber optic bundles 106 and 107 are joined into a common bundle108, which presents a common spatial area (the face of bundle 108)through which transmitted and reflected light pass. The photocell (orgenerally photo transducer) and light source 101 and 104 may beinterchangeably directed to the ends of bundles 106 and 107. Preferablythe fiber strands of the two bundles should be interspersed to ensure agreater area of acceptance of reflected light. As will be described withrespect to FIG. 4, a plurality of fibers 106 and 107 may be commoned toa single light source. The arrangement of FIG. 3a has the advantage thatthe angle of joining of bundles 106 and 107 is not critical.

FIG. 4 is a perspective illustration of a preferred scan head array foruse in the invention. Rather than employing individual light sources, asingle light source 111 is directed onto the planar face 112 of a fiberoptic bundle 110. Each of the fibers optic strands is led through aforce fitting sleeve 113 into a linear channel 114 in block 116. Arectangular semi-transparent mirror 117, the halfsilvered side of whichis directed toward the file folder, is disposed at 45 within a channelcut for that purpose in block 116. A portion of the light from the opticfiber strikes the surface of the mirror 117 and is reflected throughchannel 118 and focusing lens 119 onto the surface of the file folder.Light reflected from the surface passes through lens 119, channel 118 (aportion of which 118 is on the other side of the semi-transparent mirror117) and onto the transducing photocell 120; where a signal representingthe energy transmitted from the top of the file folder appears aselectric energy on leads 121.

Block 116 which is preferably cut from a black body or is later paintedblack includes a number of pairs of channels 118 and orthogonal channels113 equal to the number of areas to be evaluated. The output ofphotocells 121 is lead through conventional threshold limiting andamplifying circuits (not shown) to a comparator as will be explained.

The described arrangement permits the introduction of a great number ofread heads within a very small area while the single source conceptobviates the possibility of individual sources burning out and producingwrong indications when white areas are reported back as black.

Operation The typical operation for the random access store according tothe invention will now be described with reference to the circuit blockdiagram of FIG. 9 in conjunction with those figures previouslydiscussed. In order to aid the reader, that figure which best depictsthe component under consideration will be added in parentheses.

In order to extract the desired file folder from among the verticallyaligned racks, keyboard 30 is actuated by serially depressing keys 36;each of which is assigned to a numeral from 0 through 9. Each numeralimpression is forwarded to a decimal to binary converter where theseries decimal presentation is converted into a parallel binary form.

' Circuit 130 could be any of the well known types of decimal to binaryconverters, and thus will not be discussed at length. The subsequentdepression of Search key 35 simultaneously triggers drive motor controlcircuit 131 and causes the converted code to be entered in a bufferstore 133. It is the function of the buffer store to permit a comparisonbetween the codes being ascertained by the read head assemblies and theentered code designating the desired folder. Accordingly, the bufferstore may, for example, comprise a simple matrix of ferrite cores to beinterrogated by the comparators in a conventional manner.

If the number being inserted has been incorrectly entered, the operatormay press a clear key 34 which will erase the buffer store and permitthe reintroduction of the correct number.

As mentioned, key 35 also initiates the drive motor control circuit 131thereby driving each of the scanning assemblies A, B, and C as shown inFIG. 5. Each of the read head assemblies A, B and C is triggered in themanner previously described by the read command signal available atphotocell 122 from each file folder (FIG. 4) and transmits a signal tothe respective comparators A, B and C. This signal is a parallel binarypresentation of the complete code designating that file folder.

When a comparison is effected by one of the comparators, the signal isemployed via OR gates 136 and 137 to signal the drive motor controlcircuit 131, and simultaneously set a relay corresponding to thecomparator in the ejection control circuit 140.

Since each of the scanning assemblies A, B and C includes considerableinertia, it is impractical for the drive motor and drive motor controlcircuit to be designed in such a manner as to instantaneously stop thescan. Rather, the comparators signal is employed to reverse the voltageof DO drive motor 141. Depending upon inertia considerations,'this maybe sufficient to permit the scanning assemblies (which have not speededup greatly) to be stopped. instantaneously by cutting off the drivemotor voltage when a second comparison is effected in the reversedirection. 7

As will be appreciated by those skilled in the art, if the inertia ofthe scanning assemblies is too great and more damping must necessarilybe introduced, then a reverse voltage may be applied onlyinstantaneously followed by a lower voltage, thereby permitting thescanning assemblies to return to the overshot file folder at decreasedspeed. Alternatively, the scanning assembly may be permitted toovershoot the file folder again in the reverse direction, againreversing the voltage, and finally stopping at the desired file folderthrough a series of decreasing oscillations. Another arrangement wouldprovide a second read head assembly on each scanning assembly. In thiscase, the first read head assembly to reach the desired folder wouldcause a decrease in speed allowing the scanning assembly to be stoppedwithout direction reversal.

These and' other methods will be apparent to those skilled in the art;since the instant invention is not de pendent upon the precise manner inwhich the scanning assembly is stopped at the desired folder, and sinceprecise control of DC. motors is a well known art, these arrangementswill not be discussed at greater length.

Presuming now that the scanning assembly has stopped at the desired filefolder, the drive motor is now quiescent. This condition will beindicated to the ejection control circuit by the drive motor controlcircuit 131. Since a relay corresponding to the particular read head hasalready been set, the corresponding ejection mechanism in scan assemblyA, B or C may be actuated and via the motor lead screw arrangement shownin FIG. 2, the lever arm 65 progressed to project the file folder fromthe rack. The initiation of the ejection control circuit simultaneouslytriggers the annunciator to indicate folder found and erases the bufferstore; thus permitting the operator to inject the next code designationinto 143. The alignment stop circuit in turn will cause the annunciationof the alignment stop phrase. The scanning assemblies meanwhile willcome to a halt under the influence of the drive motor control circuit131 signalled via OR gate 137 as previously explained. While thealignment stop circuit may take the form of a simple mechanical relay, acontactless transistor switching circuit would be preferred.

Limit switches 132 and 134 shown in FIGS. 5 and 9 are disposed at eachend of the rack for engagement by one of the scan assemblies. Thepurpose of the limit switches is to reverse the direction of the scanassemblies when an excursion extreme has been reached. The limitswitches are coupled to the drive motor control circuit 131 through ORgate 144 to effect this result.

A logic circuit 147 is coupled both to the keyboard search button 35 andlimit switches 132 and 134. When the scan has been initiated andthereafter the scan assemblies traverse both limit switches seriatum,this circuit will initiate the annunciated phrase not in file. Logiccircuit 147 may be of a simple AND/OR Boolean type whose logic isreinitiated each time search key 35 is depressed. The output of logiccircuit 147 is also employed to erase buffer store 133 in a similarmanner to that which would follow the energization of the ejectioncontrol circuit 140.

Automatic input Where a great number of file folders are beingrequested, it is often desirable to have the code numbers introducedautomatically. To this end, a punched tape reader 45 (commonly called aTD) is provided at the console 20.

Upon the insertion of the tape into the TD, a tape read input 32 onkeyboard 30 is depressed initiating tape feed (via OR gate 150) and thetransmission of signals to a second input on converter which isactivated via button 32. This second input is adapted to react to adifferent code (generally M out of N), but provides a similar binarypresentation to the buffer store 133.

Upon the occurrence of either the folder found or not in file signals,TD 45 again advances the tape by virtue of the signal appearing on ORgate 150. At the head of each code designation, there is provided anarbitrary code to initiate the search. This code is recognized by adecoder 149 which initiates the scanning circuitry similarly to thekeyboard search key 35. The TD is programmed to stop at the end of eachcode designation and at the end of the tape (generally by providinginformationless spaces).

When the folders have been collected and utilized in the manner desired,they may be replaced anywhere in the system where an open space exists.This is one of the most significant advantages of the random accesssystem which reduces to an absolute minimum the time necessary to returna folder. With conventional file drawers, it must be remembered that thetime it takes to return a folder is generally the same as that to findit in the first instance.

Automatic collection of ejected folders FIGS. 7 and 7a illustrate amodification of the invention for automating the collection of theejected file folders. The system is predicated upon the unique abilityof the read head to view rectilinearly.

'In front of each vertical array of racks, there is provided a standard161 which is advanced between a pair of horizontal guide rails (only theupper one of which 162 is shown) via cable 164. Standard 161 bears threeindividual read heads D, E and F angled downwardly at an acute angle tohorizontal. Each of the read heads is directed to a strip ofRetroflective tape (respectively D, E and F) running the length of therack.

When the collecting mechanism has been energized, and the manner inwhich this is accomplished and the attendant control arrangements willbe discussed presently, standard 164 advances along the rack each of theheads D, E and F viewing their respective tapes.

An ejected file folder, for example folder 165, will intercept the lineof sight between the read head and the reflective tape. The reduction ofphotocell output below threshold is employed via an inverter circuit toproduce a signal, causing the acquiring mechanism 167 to index over tothat read head. Upon reaching its position, arm 168, having at its end amagnet 169, advances towards the top of the folder until it engagesmetallic piece 170; aflixed to each folder for the purpose of automaticcollection. At this point which is coincident with the end of itstravel, arm 168 automatically reverses drawing the folder out of therack and onto the lower guide rail 171. When arm 168 has been fullyretracted, file folder 165 has cleared the rack and standard 161 may beadvanced to either end of the storage area where the file folder isremoved.

FIG. 7a shows a circuit block diagram for effecting the foregoingresult. The folder found signal, which triggers the console annunciator,may be employed to initiate the horizontal drive control 180 which inturn causes motor 182 to advance standard 161 via cable 164. Limitswitches 184 (not shown in the perspective of FIG. 7) cause an automaticreversal of the drive when the folder-acquiring-standard reaches eitherend. Upon an ejected folder being ascertained by one of the read heads,the horizontal drive control is signalled through OR gate 186 to stopthe scan. This may of course be in the same oscillatory or damped manneras described in conjunction with the stopping of the scanningassemblies. As soon as one of the read heads has recognized the ejectedfolder and before horizontal motion has stopped, vertical indexing ofthe acquisiton mechanism begins under control of the vertical indexingcircuit 188. This circuit is pre-programmed in any well known manner toone of three vertical positions. When it assumes any one of thesepositions, it automatically triggers the acquisition circuit 190 whichin turn initiates the movement of the acquisition arm 168.

Since solenoids, servo mechanisms, rachet and lead screw arrangementsare all well known in the art, and each provides satisfactory resultsfor driving the acquisition mechanism 167 vertically and acquiring arm168 horizontally (depending upon the weight of the file folder,advancing speed, etc.) they will not be discussed further. Suffice it tosay that limit and reversing switches are appropriately placed withrespect to such mechanisms toachieve the desired functional result.

After the acquisition has been accomplished and the acquiring arm 168has traversed both directions, acquisition circuit 190 triggers thehorizontal drive control 180 to return the acquisition standard 167 inthe desired direction to the point of collection or home positiongenerally at one end of the rack. Unlike the scan assemblies where theinitial direction of advance is left to chance, here the initial advanceis always the same and the last or first motor control command must beto reverse direction.

Simultaneous ejection and folder return Where the system described withrespect to FIG. 7 is being used, it is hazardous to return file foldersto the rack while the equipment is being used since slightmiscalculation would certainly produce injury from the high speedstandard.

The embodiment shown in FIGS. 8 and 8a obviates the foregoing problemand adds the significant advantage of simultaneous collection and returnof folders from and to the system. In this embodiment, the codedesignations, rather than being Written on the tops of the folders, arewritten on the sides where they can be viewed by scanning assembliestraversing in a direction similar to that described previously butorthogonally disposed in attitude. This permits the elimination of thescanning assemblies between the racks and increases the vertical rackarea. As a practical matter, approximately a 25% saving is effected. Thearrangement shown in FIG. 8 both conceptually and electrically workssimilarly to that described in connection with FIG. 9. Instead of threeread head assemblies advancing simultaneously to read the I folder tops(although the embodiment of FIG. 1 may be easily modified to any numberof racks) six read head assemblies simultaneously scan the folder sides.Alignment problems are virtually eliminated with this arrangement sincea horizontal displacement of a file folder is ineffective to promoteerroneous readings. Thus, the alignment stop mechanism shown in FIG. 9is not a necessary feature of this embodiment.

The file folders are inserted into the racks on the sides opposite tothe traversing scan column 201 (the horizontal dimension of which hasbeen exaggerated to permit the viewing of both racks simultaneously inthe perspective). The folder is inserted with its coded area forwarduntil it strikes magnetic bar 203, which is engaged by a metallic piece204 affixed to the folder.

Magnetic bar 203 rather than being continuous as was the previous caseis segmented coextensive with each of the rack sections 205, 206, 207,etc. Each magnetic bar rides slots in a pair of non-magnetic (forexample, aluminum) guides 208 and 209 juxtaposed to similarly embracethe bar. When the scanning column had stopped opposite the designatedfile folder, the read heads, motor control circuit, etc. operatesimilarly to that previously described and ejection arm 210, including amagnetic end piece 211, advances toward the designated file folderdirected at the metallic portion thereof. Arm 210 is controlledsimilarly to lever arm 65 by the ejection control circuit 140. When arm210 has progressed sufliciently to intercept a light beam communicatingbetween source 212 and photocell 213, a conventional inverter typecircuit is actuated to energize solenoid 215 which retracts, picking upbar 203. Arm 210 continues its course, engaging the magnetic stop 204 onthe file folder and thereupon reverses, under control of the ejectioncontrol circuit, withdrawing the file folder from the rack.

Full seating of ejection arm 210 in its extreme retrograde position hasresulted in the file folder being wiped off magnet 211 by the stop 216mounted on each read head assembly.

Similar circuit functions and commands thereupon issue to initiate thenext search. The withdrawal of arm 210 re-establishes the communicationbetween the light source and photocell and de-energizes solenoid 215permitting magnetic bar 203 to drop. Since the ejected file folder isnow in the path, the bar will remain up until the folder is removed by aperson collecting the folders.

Since an up position of the bar 203 would allow a folder inserted fromthe other side to pass completely through the rack or at the leastassume an improper position horizontally, switch 218 is positioned to beclosed upon the picking up of the bar. This switch is connected to alight on the reverse side of the rack to indicate to one replacing filefolders to do so in another rack portion.

Thus, the embodiment of FIG. 8 permits not only a greater efficiency inthe manual insertion and removal of file folders, but it also permits agreater savings of space. At this juncture, it must be remembered thatthe scanning standard 201 may have an extremely small horizontaldimension equivalent to that in FIG. 7,

It is also possible to combine the ejection mechanism of FIG. 8 to awithdrawal and collection mechanism similar to that shown in FIG. 7. Tothis end, it is possible .13 H to cause the scanning heads to withdrawthe file folders, not only the ejection distance, but fully off the rackthereafter pivoting 180 by means not shown and stor-. ing the filefolders within column 201 (which will this time take a more box-likeform).

economically by means of a memorya'djunctQTlie ar:

pose of such an adjunct may be many-fold. First, it may contain arecapitulation of those files withdrawn from the system allowing ahigher speed search to be initiated through the memory than can bephysically accomplished by traversing the file folders. Thus, in amatter of a fraction of a second the memory could trigger theannunciation of not in file. Second, the memory may serve the purpose oflocating removed files by storing a code representative of the personwho last requested the file folder. These and other functions willbecome apparent as the system is explained with respect to FIG. 9a.

FIG. 9a may be considered as a substituted block diagram for thoseblocks shown within the dotted lines in FIG. 9. When desiring toinitiate a search for a particular file folder, the console operatorkeys in numerals desighating the file folder, and also a code denotingthe identity of the requester.'Ihis latter information may be providedby an auxiliary set of keys (not shown) or by serial keying in of arequester code. Upon initiating the search key in the manner previouslydescribed, the information is transmitted to converter 151 whichpresents the information in a manner acceptable to memory 152. Memory152 is for example, a multi-head, multi-track magnetic drum. Theconverted signal from keyboard 30 is temporarily stored in a bufferportion 152 of the drum (one track) in order to interrogate the memorywith the code designation of the file folder. If the memory has no suchnumber stored after a high speed scan, it signals the keyboard 30' toinitiate the search. This may be simply accomplished by triggering thekeyboard search key.

When the file folder has been found and ejected via eject controlcircuit 140, buffer store 133 will be erased in the usual manner underthe control of the signal from the eject control 140. This signal may besimultaneously employed to enter the content of buffer store 152associated with memory 152, into the memory thereby storing thedesignation of the file folder and the requester.

Assuming now the same folder is requested, subsequently theinterrogation of memory 152 will initiate a recognition of this filefolder as one which had been removed. Memory 152 will thereupon issue adisplay signal which will simultaneously trigger the annunciation of notin file as well as an auxiliary annunciation of the person who hasrequested the file and now has it in his possession. This may be ineither code form which may be referred to in a cross index or theannunciation may take place by means of a converter (not shown) toannunciate the persons name.

Upon return of the file to the storage rack, it is first placed on readplatform 153 which contains an individual scan assembly. The placing ofthis file on the platform causes a scan initiator to traverse the readassembly over the file folder. The scan initiator may take the form of aphotocell arrangement whose light is intercepted by a file folderthereby causing a read head assembly to traverse once over the filefolder. Needless to say, a plurality of file folders may besimultaneously returned. Where the return is to be generally of singlefile folders, the read head assembly need not move. Rather, the filefolder may be inserted between guides; automatically triggering a staticread. The signals emanating from the read head assembly are transmittedto a second buffer 152" within memory 152. Memory 152 is automaticallysearched for the file folder code designation and erased to obviate thenot in file annunciation.

Remote read platforms 154, 155, etc. may be placed at arbitrarylocations. These read platforms are intended to modify memory 152 when afile folder is passed be tween persons without being returned to therack. In such afcase, the folder is placed upon the remote read platformand the number of the new file folder possessor keyed in on theassociated key 154', 155, etc. This information is passed tobufferl152'5' of ,.memory ,15 2; the memory being interrogated for anidentical code designation and the code number 'of the new possessor ofthe file folder substituted.

The foregoing arrangement is particularly suitable to automaticinventory control. For this purpose, memory 152 may be provided with aninventory read out 157 which provides a complete print out of those filefolders which are removed from the system as well as the names of thepersons who possess the folders. The print out would be initiated andtake place in a similar manner to conventional print outs from memories.

While the principles of the invention have been described in connectionwith specific apparatus, it is to be clearly understood that thisdescription is made only by way of example and not as a limitation tothe scope of the invention as set forth in the objects thereof and inthe accompanying claims.

What is claimed is:

1. A read head assembly for scanning spatially aligned markings made upof code elements comprising:

a substantially rectangular block having a first plurality of channelsspaced to correspond to the coded element spacings and communicatingbetween said first and second opposing faces of said block;

a semi-transparent mirror angularly disposed in said block to similarlyintercept each of said plurality of channels;

said block including a second plurality of channels each co-planar witha corresponding one of said first plurality of channels and intersectingsaid first plurality of channels at said mirror, said second pluralityof channels communicating with a third face of said block;

point source means for directing light to each of the channels of one ofsaid first and second plurality of channels and to the respective codeelement areas;

means for rendering all of said source means, one of active andinactive, simultaneously; and

a plurality of photo transducers, each disposed to intercept light fromone of the channels of the other of said first and second plurality ofchannels.

2. The read head assembly claimed in claim 1 wherein said first andsecond plurality of channels are orthogonal with respect to one anotherand wherein said semi-transparent mirror is at an angle of 45 withrespect to each of said first and second plurality of channels.

3. The read head assembly claimed in claim 1 wherein said point sourcemeans and rendering means comprises:

a remote light source; and

a fiber optic array having a bundled end adjacent said light source, theindividual fibers being divided among said one of said first and secondplurality of channels for the transmission of light thereto.

4. A read head assembly as claimed in claim 1, wherein said point sourcemeans directs the light to said second plurality of channels and whereinsaid first plurality of channels are parallel and spaced by a distanceequivalent to the code element spacings.

References Cited UNITED STATES PATENTS 2,410,104 10/ 1946 Rainey.

3,034,643 5/1962 Keller et al.

3,068,739 12/1962 Hicks et al 250-227 X 3,124,675 3/1964 Epstein.

(Other references on following page) UNITED STATES PATENTS j OTHERREFERENCES v Barber, 21 Ways To Pick Data 011 Moving Objects,

Part 1: Light as the Transfer Medium, Control Engi- Schwerdt et nearing,October 1963, pp. 82-86.

?fi RALPH G. NILSON, Primary Examiner Kissinger 250227 X 5 M. ABRAMSON,Assistant Examiner Hargens 250227 US. 01. X.R.

